Mechanism for detecting opening of locks



(No Model.)

G. SMYTH. I MECHANISM FOR DETECTING OPENING OF. LOCKS.

Patented Dec. 4, 1894.

WITNESSES: $4M gay/2Z4 BY ATTOH/YEY. I

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UNITED STATES PATENT 01mins.

- CHARLES SMYTH, or DAYTON, OHIO.

MECHANISM FOR DETECTING OPENING OF LOCKS.

SPECIFICATION forming part of Letters latent No. 530,133, dated December4, 1894.

Application filed February 8, 1894- Serial No. 499,555 (No model.)

art to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the letters of reference markedthereon, which form a part of this specification.

This invention relates'to improved mechanism for detecting theunauthorized opening of looks.

The invention may be applied to the locks of various articles, but it ismore especially designedfor use on the locks of cash regison wheel (19).The object of the invention is to provide:

ters.

certain and reliable means for ascertaining whether or not said lockshave been opened.

To this end said improved mechanism c011- sists of a series of wheelsbearing numerical and alphabetical characters that are made visiblethrough sight openings, and of other adjunctive mechanism, all of whichwill be described in the specification and is shown in the annexeddrawings, of which- Figure 1 is a view of the mechanism with the plate Aremoved and showing the shaft E in section, and the relative positionsof the wheels; Fig. 2, a view of a lid with parts thereof broken away,showing in dotted lines, the lock, key-hole and wheels; Fig. 3, a rearview showing in dotted lines the wheels with certain characters thereonvisible through sight openings in the rear case; Fig. 4:, a horizontalsection through part of the front of the lid, and the rear caseinclosing the mechanism, the lock being removed in this View; Fig.

5, detached, detail views of the shaft carrying the ratchet pawls andthe key-hole plate: Fig. 6, a detached detail view of the ratchet wheelby which the primary transfer is made; Fig. 7, a detached detail view oftheirregular ratchet toothed wheel upon which the alphabeticalcharacters are stamped.

In the specification, similar letters of reference will indicatecorresponding parts throughout the several views.

A designates a plate attached to the inner side of the front portion ofthe lid B, and O is a similar plate attached to the outer side of saidlid, and between which plates a recess D is provided for the lock, thebolt (a) of which, is shown, projected to a'locked position in Fig. 2. Eis a shaft loosely journaled in said plates, upon the inner end ofwhich, is loosely mounted a ratchet wheel (b) having stamped on itsinner face in irregular order, the letters of the alphabet. It will benoted, the ratchets formed on the wheel (1)) are likewise irregular.This arrangement of said teeth and letters is an important feature of myinvention and will again be referred to hereinafter.

(c) designates an arm rigidly mounted on the inner end of the shaft E,having a ratchet pawl (42') that engages with the ratchet teeth (d)denotes a ratchet wheel having numbers in regular order from 1 to 9stamped upon its inner face, and which are visible one at a time throughthe sight opening (e). See Fig. 3. This wheel is loosely mounted uponthe shaft E and adjacent to the arm (0) so that said wheel is engaged bythe ratchet pawl c) mounted on the inner side of the arm (0).

e) is a tooth projecting from the periphery of this wheel, which uponevery revolution of said wheel, moves an adjacent wheel (f) which inturn, upon a complete revolution, moves with the tooth (6") a furtherwheel These wheels (f) and (g) are mounted on the inner side of theinclosing case F, which is secured to. the plate A, and are providedwith facial letters similar to thoseon wheel (d),

and peripheral teeth (1') arranged in pairs, between which, the teeth(e) and (6") engage to move said wheels.

(4) is a key-hole plate rigidly attached to arm, only in one direction,and that move ment is imparted to them whenever the keyhole plate (2')is slid away from the key-hole.

The following briefly illustrates the working of the devicez-When thelid is locked, the wheels have been previously set to exhibit certaincharacters through the sight openings; an example of which is shown inFig. 3, a note of which is made. Should an attempt be made to open thelid, the removal of the plate (r) from the key-hole will necessarilyhave to take place. This will rotate the ratchet wheels (11) and (d) thenumerical characters on the latter wheel being changed to appear attheir sight opening in the progressive order, while the alphabeticalcharacters on the wheel (1)) appear irregularlysee Fig. 7and themovement of said wheel is correspondingly irregular owing to thevariation in the ratchet teeth thereof. The result is that while thewheels bearing the numerals might possibly be made to re-exhibit thesame characters at their respective sight openings, by considerableeffort in turning the wheels, the irregular arrangement and constructionof the wheel (1)) renders a return of the same letter a far morediliicult if not an impossible task, as the person manipulating theapparatus is not supposed to know the order in which the letters arearranged, or the extent of each movement of the wheel. Therefore hewould have to rely altogether upon chance, in an eitort to get all ofthe Wheels back to their former positions. It will thus be seen that thewheel (1)) is designed to puzzle those who are not familiar with thecombination or arrangement of the letters thereon, and the variations inthe extent of its movements. The person orpersons having authority overthe apparatus upon which the device is used, are of course familiar withthis wheel, therefore may know what letter will appear at its sightopening upon every movement of said wheel.

Having described my invention, I desire to secure by Letters,Patent- 1.The herein described mechanism for dotecting the opening of the lids ofcash registers or other apparatus, consisting of a shaft with a key-holeplate, and an arm rigidly attached thereto, said plate normally closingthe key-hole of a look, a wheel having irregularly disposed ratchetteeth on its periphery, and characters on its face, said charactersbeing placed thereon in irregular order, a ratchet wheel of smallerdiameter provided with characters on its face, both of said wheels beingloosely mounted on said shaft, ratchet pawls pivoted on said arm wherebysaid wheels are rotated when the key-hole plate is moved from thekey-hole, and different characters are thereby made to appear throughsight openings beneath the lid, substantially as herein described.

2. The combination of the shaft with the key-hole plate, and the arm,rigidly mounted thereon, ratchet pawls pivoted on said arm, the wheel(11) provided with irregular teeth, and characters stamped in irregularorder on its face, the ratchet wheel ((1) bearing characters upon itsface, both of said Wheels being loosely mounted on the shaft,substantially as described.

3. The combination of the shaft with the key-hole plate, and the armrigidly attached thereto, ratchet pawls pivoted to said arm,

the wheel (1)) provided with irregular peripheral ratchet teeth, andirregularly stamped characters on its face, and the toothed wheels (f)and (g) bearing characters upon their faces, the wheel (f) beingactuated by the wheel (d) upon one revolution thereof, and the wheel (g)being actuated upon one revolution of the wheel (f), substantially asherein described.

In testimony whereof I have hereunto set my hand this 27th day ofJanuary, 1894.

CHAS. SM Ylll.

Witnesses:

R. J. MCCARTY, S. A. DIoKsoN.

